An acoustic apparatus disposing a horn or an acoustic pipe before a speaker for leading the sound waves emitted by the speaker to an opening has been widely used hitherto because of the advantages as compared with the constitution without using horn or acoustic pipe, such as acquisition of high sound pressure output and radiation of sound waves In a specific direction.
In the television receiver Incorporating such speakers, an acoustic pipe mounting a speaker Is disposed along a cathode-ray tube for image display, and the television cabinet is located along the acoustic pipe, so that the television receiver is small and slim.
Inside the acoustic pipe, absorption members and reflection plates are disposed depending on the length and shape of the acoustic pipe, and the acoustic characteristic is improved.
In such apparatus, as a result of too much attention paid to the small and slim structure of the receiver, the area of the section and opening of the leading part for guiding the sound waves from the acoustic pipe is too narrow, which has influenced the acoustic quality and lowered the output sound pressure.
In an apparatus having a bass-reflex port for bass register for enhancing the bass register disposed closely to the acoustic pipe, interference of radiation sound wave from the acoustic pipe occurs, which has caused sound pressure frequency characteristics of extreme peak dip.
Besides, for the purpose of downsizing, the magnetic circuit of the speaker is too close to the cathode-ray tube, and the image is disturbed by the leakage magnetic flux from the magnetic circuit.